Weekly Puzzle#1: Guess, what this code does?

No copy-past and compilation, please! Try to understand, what this Java code does just reading it. Be honest with yourself, cheaters die along :)

// Java program to print ***
public class Secret
public static void main(String[] args)
String str = "ABC";
int n = str.length();
Secret secret = new Secret();
secret.doYourDance(str, 0, n-1);


Using try-with-resource statement working with BufferedReader in Java

Working with BufferedReader and it's variants in Java was always a bit of a pain: developers need to not to forget close it and do the IOException handing doing it, not to mention about bunch of null-checks. Otherwise you program work could be interrupted with the most surprising and unpleasant way possible.
Prior the Java 7 we had to do smth. like this:

String readFirstLineFromFileWithFinallyBlock(String path)

Android P at the First Glance

Android 9 (Pie) available for developer preview! We've spent some time playing around and this is what we've found out.